Mussel adhesive proteins (MAPs) are remarkable underwater adhesive materials secreted by certain marine organisms which form tenacious bonds to the substrates upon which they reside. During the process of attachment to a substrate, MAPs are secreted as adhesive fluid precursors that undergo a cross-linking or hardening reaction which leads to the formation of a solid adhesive plaque. One of the unique features of MAPs is the presence of L-3-4-dihydroxyphenylalanine (DOPA), an unusual amino acid which is believed to be responsible for adhesion to substrates through several mechanisms that are not yet fully understood. The observation that mussels adhere to a variety of surfaces in nature (metal, metal oxide, polymer) led to a hypothesis that DOPA-containing peptides can be employed as the key components of synthetic medical adhesives or coatings.
In the medical arena, few adhesives exist which provide both robust adhesion in a wet environment and suitable mechanical properties to be used as a tissue adhesive or sealant. For example, fibrin-based tissue sealants (e.g. Tisseel V H, Baxter Healthcare) provide a good mechanical match for natural tissue, but possess poor tissue-adhesion characteristics. Conversely, cyanoacrylate adhesives (e.g. Dermabond, ETHICON, Inc.) produce strong adhesive bonds with surfaces, but tend to be stiff and brittle in regard to mechanical properties and tend to release formaldehyde as they degrade.
Therefore, a need exists for materials that overcome one or more of the current disadvantages.